One of the most persistent and troublesome problems arising during modern fabric laundering operations is the tendency of some colored fabrics to release dye ("fugitive dye") into the laundering solutions. The dye is then transferred onto other fabrics being washed therewith.
One way of overcoming this problem would be to bleach the fugitive dyes washed out of dyed fabrics before they have the opportunity to become attached to other articles in the wash.
Suspended or solubilized dyes can to some degree be oxidized in solution by employing known bleaching agents.
GB 2 101 167 describes a stable liquid bleaching composition containing a hydrogen peroxide precursor which is activated to yield hydrogen peroxide on dilution.
However, it is important at the same time not to bleach the dyes actually remaining on the fabrics, that is, not to cause color damage.
U.S. Pat. No. 4,077,768 describes a process for inhibiting dye transfer by the use of an oxidizing bleaching agent together with catalytic compounds such as iron porphins.
U.S. patent application 421,414 describes peroxidases and oxidases utilized for the oxidation of organic or inorganic substances, including colored substances.
A dye transfer inhibiting composition comprising an enzymatic system capable of generating hydrogen peroxide and iron catalysts has been disclosed in copending EP Patent Application 91202655.6, filed Oct. 9, 1991.
EP 424 398-A describes a detergent additive capable of exerting a bleaching effect comprising a peroxidase. The additive further comprises one or more enzymes, particularly a lipase, protease, amylase or a cellulase.
Peroxidase enzymes are bleaching enzymes which have been proposed for dye transfer inhibition. It has been determined that to achieve good dye bleaching, particularly at high pH levels, e.g., levels above about 8 or 9, an accelerator is required for the peroxidase enzyme. It has now been surprisingly found that the efficiency of peroxidases in terms of dye transfer inhibition, particularly at pH above about 9, is considerably enhanced by using an accelerator, preferably a phenothiazine or phenoxazine accelerator together with the peroxidase. It is therefore an object of the present invention to provide dye transfer inhibition systems or detergent compositions containing such dye transfer inhibition system which exhibit optimum dye transfer inhibition in wash solutions by using said peroxidase in conjunction with a phenothiazine accelerator.
According to another embodiment of this invention a process is also provided for laundering operations involving colored fabrics.